scholarly journals Wheat photosystem II heat tolerance responds dynamically to short and long-term warming

2021 ◽  
Author(s):  
Bradley C Posch ◽  
Julia Hammer ◽  
Owen K Atkin ◽  
Helen Bramley ◽  
Yong-Ling Ruan ◽  
...  
Keyword(s):  
Heat Stress ◽  
Photosystem Ii ◽  
Heat Tolerance ◽  
Genotypic Variation ◽  
Tolerance Analysis ◽  
Grain Filling ◽  
Intraspecies Variation ◽  
Interspecies Variation ◽  
Key Factor ◽  
High Throughput Phenotyping

Heat-induced inhibition of photosynthesis is a key factor in declining wheat performance and yield. Variation in wheat heat tolerance can be characterised using the critical temperature (Tcrit) above which incipient damage to the photosynthetic machinery occurs. We investigated intraspecies variation and plasticity of wheat Tcrit under elevated temperature in field and controlled environment experiments. We also assessed whether intraspecies variation in wheat Tcrit mirrors patterns of global interspecies variation in heat tolerance reported for mostly wild, woody plants. In the field, wheat Tcrit varied through the course of a day, peaking at noon and lowest at sunrise, and increased as plants developed from heading to anthesis and grain filling. Under controlled temperature conditions, heat stress (36°C) was associated with a rapid rise in wheat Tcrit (i.e. within two hours of heat stress) that peaked after 3—4 days. These peaks in Tcrit indicate a physiological limitation to photosystem II heat tolerance. Analysis of a global dataset (comprising 183 Triticum and wild wheat (Aegilops) species) generated from the current study and a systematic literature review showed that wheat leaf Tcrit varied by up to 20°C (about two-thirds of reported global plant interspecies variation). However, unlike global patterns of interspecies Tcrit variation which has been linked to latitude of genotype origin, intraspecific variation in wheat Tcrit was unrelated to that. Yet, the observed genotypic variation and plasticity of wheat Tcrit suggests that this trait could be a useful tool for high-throughput phenotyping of wheat photosynthetic heat tolerance.

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. II. Fractional Protein Accumulation

1996 ◽  
Vol 23 (6) ◽  
pp. 739 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Size Exclusion ◽  
Protein Accumulation ◽  
Wheat Varieties ◽  
Grain Filling Period ◽  
Very High

Short periods of very high temperature (> 35�C) are common during the grain filling period of wheat, and can significantly alter mature protein composition and consequently grain quality. This study was designed to determine the stage of grain growth at which fractional protein accumulation is most sensitive to a short heat stress, and to examine whether varietal differences in heat tolerance are expressed consistently throughout the grain filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley, tolerant and sensitive, respectively) were exposed to a short (5 day) period of very high temperature (40�C max, for 6 h each day) at 5-day intervals throughout grain filling, from 15 to 50 days after anthesis. Grain samples were taken throughout grain growth and analysed for protein content and composition (albumin/globulin, monomer, SDS-soluble polymer and SDS-insoluble polymer) using size-exclusion high-performance liquid chromatography. The timing of heat stress exerted a significant influence on the accumulation of total wheat protein and its fractions, and protein fractions differed in their responses to the timing of heat stress. Furthermore, wheat genotype influenced both the sensitivity of fractional protein accumulation to heat stress and the stage during grain filling at which maximum sensitivity to heat stress occurred.

scholarly journals Screening the FIGS Set of Lentil (Lens culinaris Medikus) Germplasm for Tolerance to Terminal Heat and Combined Drought-Heat Stress

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1036
Author(s):  
Noureddine El haddad ◽  
Karthika Rajendran ◽  
Abdelaziz Smouni ◽  
Nour Eddine Es-Safi ◽  
Nadia Benbrahim ◽  
...  
Keyword(s):  
Heat Stress ◽  
Drought Stress ◽  
Heat Tolerance ◽  
Lens Culinaris ◽  
Genotypic Variation ◽  
Tolerance Index ◽  
Cool Season ◽  
Good Source ◽  
Protein Fiber ◽  
Iron And Zinc

Lentil (Lens culinaris Medikus) is one of the most important cool season food legume crops grown in many countries. Seeds are typically rich in protein, fiber, prebiotic carbohydrates and minerals, such as iron and zinc. With changing climate and variability, the lentil crop faces frequent droughts and heat stress of varying intensity in its major production zones. In the present study, a set of 162 lentil accessions selected through the Focused Identification of Germplasm Strategy (FIGS) were screened for tolerance to heat stress and combined heat-drought stresses under field conditions at two contrasting locations, namely Marchouch and Tessaout in Morocco. The results showed a significant genotypic variation for heat tolerance and combined heat-drought tolerance among the accessions at both locations. Based on the heat tolerance index (HTI), accessions, namely ILL 7833, ILL 6338 and ILL 6104, were selected as potential sources of heat tolerance at Marchouch, and ILL 7814 and ILL 8029 at Tessaout. Using the stress tolerance index (STI), ILL 7835, ILL 6075 and ILL 6362 were identified as the most tolerant lines (STI > 1) at Marchouch, and ILL 7814, ILL 7835 and ILL 7804 (STI > 1) at Tessaout, under the combined heat-drought stress conditions. Accession ILL 7835 was identified as a good source of stable tolerance to heat stress and combined heat-drought stress at both locations.

Comparison of sudden heat stress with gradual exposure to high temperature during grain filling in two wheat varieties differing in heat tolerance. II. Fractional protein accumulation

1998 ◽  
Vol 25 (1) ◽  
pp. 1 ◽  
Author(s):  
P.J. Stone ◽  
M.E. Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Temperature Increase ◽  
High Performance ◽  
Protein Composition ◽  
Grain Filling ◽  
Size Exclusion ◽  
Protein Accumulation ◽  
Wheat Varieties

Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley, tolerant and sensitive, respectively) were exposed to either a sudden or gradual (6°C h-1) increase from 20 to 40°C to determine if the rate of temperature increase used in controlled-environment studies (1) alters the accumulation of functionally important proteins during grain-filling, and (2) affects the ability to discriminate between heat tolerant and sensitive varieties of wheat. After heat treatment, grain samples were taken throughout grain growth and analysed for protein content and composition. Wheat proteins were separated and quantified as albumin/globulin, monomer, SDS-soluble polymer and SDS-insoluble polymer using size-exclusion high-performance liquid chromatography. The rate of temperature increase exerted a significant influence on the accumulation of total wheat protein and its fractions, and protein fractions differed in their responses to the suddenness of heat stress. The acclimation to heat stress afforded by a gradual increase to high temperature can mitigate the effects of heat stress on fractional protein accumulation, and consequently grain protein composition at maturity. Furthermore, the ability of wheat to acclimate to high temperature varies between genotypes, and this needs to be taken into account when selecting for heat tolerance.

scholarly journals Detrimental effects of heat stress on grain weight and quality in rice (Oryza sativa L.) are aggravated by decreased relative humidity

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11218
Author(s):  
Haoliang Yan ◽  
Chunhu Wang ◽  
Ke Liu ◽  
Xiaohai Tian
Keyword(s):  
Heat Stress ◽  
Relative Humidity ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Grain Weight ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Filling Stage ◽  
Head Rice ◽  
Grain Filling Stage

There is concern over the impact of global warming on rice production due increased heat stress, coupled with decreased relative humidity (RH). It is unknown how rice yield and quality are affected by heat stress and decreased RH during the grain filling stage. We conducted experiments in controlled growth chambers on six rice cultivars, varying in heat tolerance using 12 combinative treatments of three factors: two RH levels (75% and 85%), three temperature levels (the daily maximum temperature at 33 °C, 35 °C, and 37 °C), and two durations (8 d and 15 d after anthesis). Results showed that RH75% with temperature treatments significantly reduced grain weight, which was higher than RH85%. The same trend was also observed for both head rice rate and chalkiness. R168 was the most heat-tolerant cultivar, but it still had some differences in grain weight, head rice rate, and chalkiness between the two RH regimes. The lower RH was most detrimental at 35 °C, and to a lesser extent at 33 °C, but had a negligible effect at 37 °C. Our results provide a better understanding of temperature and RH’s interaction effects on rice quality during the grain filling stage, suggesting that RH should be considered in heat tolerance screening and identification to facilitate rice breeding and genetic improvement.

Effect of Timing of Heat Stress During Grain Filling on Two Wheat Varieties Differing in Heat Tolerance. I. Grain Growth

1995 ◽  
Vol 22 (6) ◽  
pp. 927 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Grain Growth ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Dry Matter Accumulation ◽  
Varietal Differences ◽  
Short Period ◽  
Grain Filling Period ◽  
Very High

Short periods of very high temperature (> 35�C) are common in many of the world's wheat growing areas and can be a significant factor in reducing yield and quality of wheat. This study was designed to determine the stage at which grain growth is most sensitive to a short period of high temperature and to examine whether varietal differences in heat tolerance are expressed throughout the whole grain-filling period. Two varieties of wheat differing in heat tolerance (cvv. Egret and Oxley) were exposed to a short (5 days) period of very high temperature (40�C max. for 6 h each day) at 5-day intervals throughout grain filling, starting from 15 days after anthesis (DAA) and concluding at 50 DAA. Responses of grain dry matter accumulation and water content to high temperature were monitored throughout grain filling, and the results compared with controls maintained at 21/16�C day/night. Varietal differences in heat tolerance were expressed throughout the grain-filling period. Mature individual kernel mass was most sensitive to heat stress applied early in grain filling and became progressively less sensitive throughout grain filling, for both varieties. Reductions in mature kernel mass resulted primarily from reductions in duration rather than rate of grain filling.

scholarly journals Rapid temperature responses of photosystem II efficiency forecast genotypic variation in rice vegetative heat tolerance

2020 ◽  
Vol 104 (3) ◽  
pp. 839-855
Author(s):  
John N. Ferguson ◽  
Lorna McAusland ◽  
Kellie E. Smith ◽  
Adam H. Price ◽  
Zoe A. Wilson ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Heat Tolerance ◽  
Genotypic Variation ◽  
Photosystem Ii Efficiency ◽  
Rapid Temperature ◽  
Temperature Responses

scholarly journals Assessment of Drought and Heat Tolerance of Durum Wheat Lines Derived from Interspecific Crosses Using Physiological Parameters and Stress Indices

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 695
Author(s):  
Hafid Aberkane ◽  
Bouchra Belkadi ◽  
Zakaria Kehel ◽  
Abdelkarim Filali-Maltouf ◽  
Izzat S. A. Tahir ◽  
...  
Keyword(s):  
Heat Stress ◽  
Durum Wheat ◽  
Heat Tolerance ◽  
Genotypic Variation ◽  
Physiological Parameters ◽  
Interspecific Crosses ◽  
Tolerance Index ◽  
Total Biomass ◽  
Highly Correlated ◽  
Wheat Lines

Drought and high temperature are the major abiotic stresses for wheat production. The present study investigated the effect of drought and chronic heat stress on physiological parameters of durum wheat lines derived from interspecific crosses and their association with yield. Seventy-seven durum wheat lines were evaluated during two seasons (2016–2017 and 2017–2018) for drought tolerance at Tessaout (Morocco) using irrigated and rainfed treatments and for heat tolerance at Wad Medani (Sudan). Five drought screening indices (alone or combined) and physiological parameters were used to assess drought and heat tolerance. Among the physiological parameters used, canopy temperature (CT) had moderate heritability and was significantly affected by both severe and moderate drought stresses. CT at early heading showed a stronger correlation with grain yield (GY) and total biomass (BY) under heat stress. The use of maximum quantum yield of PSII (Fv/Fm) for drought/heat screening was limited by the low genetic variation despite its significant correlation with yield under drought (r2 = 0.22) and heat (r2 = 0.4). The normalized difference vegetation index (NDVI) at vegetative stage was highly correlated with GY and BY and it showed high genotypic variation that can allow for efficient selection. The grain filling rate (GFR) was found to be highly correlated with GY and BY under heat stress. The modified stress tolerance index (MsSTI) had the highest association with GY under drought (R2 = 0.82) while the mean productivity (MP) was adapted to both optimal conditions (R2 = 0.77) and drought stress (R2 = 0.73). The computation of a mean score index (MSI) improved the selection efficiency under drought (R2 = 0.92). The results showed good potential for lines derived from wide crosses to increase variability for heat and drought adaptive physiological traits.

scholarly journals The Physiological Basis of Improved Heat Tolerance in Selected Emmer-Derived Hexaploid Wheat Genotypes

2021 ◽  
Vol 12 ◽  
Author(s):  
Smi Ullah ◽  
Richard Trethowan ◽  
Helen Bramley
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Stress Responses ◽  
Selection Process ◽  
Abiotic Stress Tolerance ◽  
Grain Filling ◽  
Complex Nature ◽  
Physiological Basis ◽  
Wheat Genotypes ◽  
Short Period

Wheat is sensitive to high-temperature stress with crop development significantly impaired depending on the severity and timing of stress. Various physiological mechanisms have been identified as selection targets for heat tolerance; however, the complex nature of the trait and high genotype × temperature interaction limits the selection process. A three-tiered phenotyping strategy was used to overcome this limitation by using wheat genotypes developed from the ancient domesticated wheat, emmer (Triticum dicoccon Schrank), which was considered to have a wide variation for abiotic stress tolerance. A contrasting pair of emmer-based hexaploid lines (classified as tolerant; G1 and susceptible; G2) developed from a backcross to the same recurrent hexaploid parent was chosen based on heat stress responses in the field and was evaluated under controlled glasshouse conditions. The same pair of contrasting genotypes was also subsequently exposed to a short period of elevated temperature (4 days) at anthesis under field conditions using in-field temperature-controlled chambers. The glasshouse and field-based heat chambers produced comparable results. G1 was consistently better adapted to both extended and short periods of heat stress through slow leaf senescence under heat stress, which extended the grain filling period, increased photosynthetic capacity, increased grain filling rates, and resulted in greater kernel weight and higher yield. The use of a combination of phenotyping methods was effective in identifying heat tolerant materials and the mechanisms involved.

The effect of duration of heat stress during grain filling on two wheat varieties differing in heat tolerance: grain growth and fractional protein accumulation

1998 ◽  
Vol 25 (1) ◽  
pp. 13 ◽  
Author(s):  
P.J. Stone ◽  
M.E. Nicolas
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Grain Filling ◽  
Protein Accumulation ◽  
Tolerant Variety ◽  
Heat Tolerant ◽  
Very High ◽  
Individual Kernel

Two varieties of wheat differing in heat tolerance were exposed to very high temperature (40/19°C day/night) for periods of 1–10 days duration. Responses of grain dry matter, water and fractional protein accumulation to high temperature were monitored throughout grain filling in the heat- sensitive variety, and at maturity only in the heat-tolerant variety. Results are compared with controls maintained at 21/16°C day/night. As little as 1 day of heat treatment reduced kernel mass by 14% in the heat-sensitive variety (Oxley), but by only 5% in the heat-tolerant variety (Egret). In both varieties, the reduction of individual kernel mass due to high temperature increased linearly with increased duration of heat treatment, such that after the first day of heat stress, each additional day of treatment reduced mature individual kernel mass by a further 1.6%. For a given duration of heat treatment, the difference in response of the two varieties was constant (9%), indicating that the varietal difference in heat tolerance was maintained for both brief and extended periods of very high temperature. Responses of grain water content and fractional protein accumulation to duration of heat stress are discussed.

Comparison of Sudden Heat Stress With Gradual Exposure to High Temperature During Grain Filling in Two Wheat Varieties Differing in Heat Tolerance. I. Grain Growth

1995 ◽  
Vol 22 (6) ◽  
pp. 935 ◽  
Author(s):  
PJ Stone ◽  
ME Nicolas
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Heat Tolerance ◽  
Wheat Yield ◽  
Grain Filling ◽  
Temperature Treatment ◽  
Thermal Time ◽  
High Temperature Treatment ◽  
Wheat Varieties ◽  
Individual Kernel

Two wheat varieties differing in heat tolerance were exposed to four heat treatments in order to determine if a sudden rise from ca 20-40�C caused a greater reduction of individual kernel mass than a gradual (6�C h-1) rise over the same temperature range. For the heat sensitive variety (Oxley), the reduction of individual kernel mass following sudden heat stress (26%) was greater than that resulting from a gradual heat stress of equivalent thermal time (13%) or equal days of treatment (18%). By contrast, for the heat tolerant variety (Egret), the reduction of individual kernel mass following rapid exposure to heat stress (12%) was not significantly greater than that caused by a gradual treatment of equal days duration (10%). Nevertheless, for Egret, sudden heat stress significantly reduced mature kernel mass compared with high temperature treatment of equivalent thermal time (6%). We conclude that heat acclimation may help to mitigate wheat yield losses due to high temperature and that the ability to acclimate to high temperature varies between wheat genotypes. Comparison of wheat varieties for yield tolerance to high temperature should therefore occur under conditions that allow gradual acclimation to elevated temperature.

Sign in / Sign up

Export Citation Format

Share Document